[PATCH 08/13] block: convert the blk_mq_hw_ctx attrs to use ->seq_show

Christoph Hellwig
2021-09-13T05:50:58Z

Trivial conversion to the seq_file based sysfs attributes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/blk-mq-sysfs.c | 64 +++++++++++++++++++-------------------------
1 file changed, 28 insertions(+), 36 deletions(-)

diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c
index 253c857cba47c..cae649b83bd54 100644
--- a/block/blk-mq-sysfs.c
+++ b/block/blk-mq-sysfs.c
@@ -47,29 +47,27 @@ static void blk_mq_hw_sysfs_release(struct kobject *kobj)

struct blk_mq_hw_ctx_sysfs_entry {
struct attribute attr;
- ssize_t (*show)(struct blk_mq_hw_ctx *, char *);
- ssize_t (*store)(struct blk_mq_hw_ctx *, const char *, size_t);
+ void (*show)(struct blk_mq_hw_ctx *hctx, struct seq_file *sf);
+ ssize_t (*store)(struct blk_mq_hw_ctx *hctx, const char *buf,
+ size_t size);
};

-static ssize_t blk_mq_hw_sysfs_show(struct kobject *kobj,
- struct attribute *attr, char *page)
+static int blk_mq_hw_sysfs_seq_show(struct kobject *kobj,
+ struct attribute *attr, struct seq_file *sf)
{
- struct blk_mq_hw_ctx_sysfs_entry *entry;
- struct blk_mq_hw_ctx *hctx;
- struct request_queue *q;
- ssize_t res;
-
- entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
- hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
- q = hctx->queue;
+ struct blk_mq_hw_ctx_sysfs_entry *entry =
+ container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
+ struct blk_mq_hw_ctx *hctx =
+ container_of(kobj, struct blk_mq_hw_ctx, kobj);
+ struct request_queue *q = hctx->queue;

if (!entry->show)
return -EIO;

mutex_lock(&q->sysfs_lock);
- res = entry->show(hctx, page);
+ entry->show(hctx, sf);
mutex_unlock(&q->sysfs_lock);
- return res;
+ return 0;
}

static ssize_t blk_mq_hw_sysfs_store(struct kobject *kobj,
@@ -94,39 +92,33 @@ static ssize_t blk_mq_hw_sysfs_store(struct kobject *kobj,
return res;
}

-static ssize_t blk_mq_hw_sysfs_nr_tags_show(struct blk_mq_hw_ctx *hctx,
- char *page)
+static void blk_mq_hw_sysfs_nr_tags_show(struct blk_mq_hw_ctx *hctx,
+ struct seq_file *sf)
{
- return sprintf(page, "%u\n", hctx->tags->nr_tags);
+ seq_printf(sf, "%u\n", hctx->tags->nr_tags);
}

-static ssize_t blk_mq_hw_sysfs_nr_reserved_tags_show(struct blk_mq_hw_ctx *hctx,
- char *page)
+static void blk_mq_hw_sysfs_nr_reserved_tags_show(struct blk_mq_hw_ctx *hctx,
+ struct seq_file *sf)
{
- return sprintf(page, "%u\n", hctx->tags->nr_reserved_tags);
+ seq_printf(sf, "%u\n", hctx->tags->nr_reserved_tags);
}

-static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page)
+static void blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx,
+ struct seq_file *sf)
{
- const size_t size = PAGE_SIZE - 1;
- unsigned int i, first = 1;
- int ret = 0, pos = 0;
+ bool first = true;
+ unsigned int i;

for_each_cpu(i, hctx->cpumask) {
if (first)
- ret = snprintf(pos + page, size - pos, "%u", i);
+ seq_printf(sf, "%u", i);
else
- ret = snprintf(pos + page, size - pos, ", %u", i);
-
- if (ret >= size - pos)
- break;
-
- first = 0;
- pos += ret;
+ seq_printf(sf, ", %u", i);
+ first = false;
}

- ret = snprintf(pos + page, size + 1 - pos, "\n");
- return pos + ret;
+ seq_printf(sf, "\n");
}

static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_tags = {
@@ -151,8 +143,8 @@ static struct attribute *default_hw_ctx_attrs[] = {
ATTRIBUTE_GROUPS(default_hw_ctx);

static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
- .show = blk_mq_hw_sysfs_show,
- .store = blk_mq_hw_sysfs_store,
+ .seq_show = blk_mq_hw_sysfs_seq_show,
+ .store = blk_mq_hw_sysfs_store,
};

static struct kobj_type blk_mq_ktype = {
--
2.30.2